JP4911471B2 - Biosensor marker, biosensor, and biosensor marker detection method - Google Patents

Description

  The present invention relates to a biosensor marker, a biosensor, and a biosensor marker detection method, and more particularly, a biosensor marker, biosensor, and biosensor marker detection in which detection accuracy by the sensor is improved by increasing the number of markers. Regarding the method.

  Today, biosensors are used in a wide range of fields such as protein interaction analysis, cancer treatment, DNA analysis, pathogen detection, disease diagnosis, and measurement of environment-related substances. The biosensor measures the binding between an antigen (biomaterial) that is a substance to be measured and an antibody that is a test reagent that specifically binds to the antigen, thereby qualitatively and quantitatively measures the substance to be measured.

  As a technique for measuring the binding between an antigen and an antibody, for example, there is a DNA chip that measures by color shading using a fluorescent substance. However, since the amount of fluorescent material is not stable, it is not suitable for highly accurate measurement.

  In addition, there is a biosensor using a measurement of mass change using a surface plasmon resonance measurement method (SPR) or a quartz crystal microbalance measurement method (QCM). However, sufficient sensitivity for measuring a biomaterial with a very small mass cannot be obtained, and the apparatus becomes complicated, resulting in cost problems.

  As biosensors that have been attracting attention in recent years, there are known techniques using a magnetic sensor using a giant magnetoresistive (GMR) element or Hall element that measures this magnetism using magnetic fine particles fixed with biomaterials as markers. (Patent Document 1, Patent Document 2, etc.). These are techniques that are stable in comparison with phosphors and the like, can be measured with high precision by using a highly sensitive magnetic measurement technique, and are also attracting attention from the viewpoint of automation.

  A conventional measurement method using magnetic fine particles as a biosensor marker will be described with reference to FIG. FIG. 1 is a schematic side view for explaining a marker measurement method of a conventional biosensor. A sensor unit 2 made of a GMR element, a Hall element or the like is provided on the substrate 1. A probe 3 is fixed to the upper part of the sensor unit 2. Probe 3 is selected to form a complementary strand with biomaterial 4 that may be present in the sample. In the illustrated example, the biomaterial 4 is fixed in advance to the magnetic fine particle 5, and the magnetic fine particle 5 is caught by the probe 3 by binding the biomaterial 4 to the probe 3 in a complementary manner. . Therefore, when the biomaterial 4 is present in the sample, the biomaterial 4 is caught by the probe 3 fixed in the vicinity of the sensor unit, and the magnetism of the magnetic fine particles 5 fixed to the biomaterial 4 is measured by the sensor unit 2 It is. Thereby, the presence or absence of the marker is detected.

  The size of the magnetic fine particle used as a biosensor marker is preferably not too large for the biomaterial or the probe to be fixed to the probe via the biomaterial. If the magnetic particles are too large for the biomaterial, it is possible that the magnetic particles will not be caught by the probe and will not be measured even though there is a biomaterial and probe that should originally be bound. is there. However, when the magnetic fine particles are made smaller, the magnetic properties of the magnetic fine particles are proportional to the size of the magnetic fine particles. Therefore, the smaller the magnetic fine particles, the harder it is to be detected by the magnetic sensor, and the magnetic fine particles bind to the probe via the biomaterial. In spite of this, it may happen that the presence or absence of magnetic fine particles cannot be measured.

  Many of the magnetic sensors that detect a minute magnetic field from magnetic fine particles are composed of GMR sensors. However, this has a problem of low sensitivity, and sufficient measurement sensitivity for the above-mentioned extremely small magnetic fine particles. Could not get. In addition, even a Hall sensor that can be expected to have higher measurement accuracy than a GMR sensor, for example, to measure the magnetism of extremely small magnetic particles having a particle size of 100 nm or less corresponding to the size of a single molecule DNA. However, it still cannot be said to have sufficient measurement sensitivity.

  In order to solve these problems, in Japanese Patent Application No. 2006-310712 by the same applicant as the present applicant, in order to increase the magnetic fine particles, a small magnetic particle species fixed to the probe via a biomaterial, A plurality of magnetic fine particles having the same size as this are used to apply an external magnetic field to form magnetic fine particle columns. And the marker increased in this way was measured with a magnetic sensor or an optical microscope.

Japanese translation of PCT publication No. 2003-524781 JP 2005-188950 A

  However, in the above-mentioned Japanese Patent Application No. 2006-310712, the size of the magnetic fine particle column to be formed is adjusted by an external magnetic field to be applied. When the magnetic fine particle column becomes too large, the force attracted to the magnetic field generation source side also becomes strong, and there is a possibility that the magnetic fine particle column adsorbed on the magnetic fine particle species may be separated.

  Furthermore, the above-described conventional technology cannot perform quantitative measurement of biomaterials.

  In view of such circumstances, the present invention is capable of detecting a biomaterial at low cost and with high sensitivity without using an ultra-sensitive and expensive sensor and the like, a biosensor marker capable of quantitative measurement, a biosensor, and A marker detection method for a biosensor is to be provided.

  In order to achieve the above-described object of the present invention, a marker for a biosensor according to the present invention includes a plurality of magnetic fine particle species fixed together with a biomaterial in the vicinity of a detection region of the biosensor, and a plurality of markers by applying an external magnetic field. And at least one target magnetic fine particle that is adsorbed by the magnetic fine particle species and is relatively larger than the magnetic fine particle species.

  In addition, the biosensor for detecting a biomaterial using the marker according to the present invention includes a plurality of magnetic fine particle species fixed together with the biomaterial in the vicinity of the detection region of the biosensor, and a plurality of magnetic fine particle species by applying an external magnetic field. At least one target magnetic fine particle that is adsorbed and relatively larger than the magnetic fine particle species, an external magnetic field applying means that applies an external magnetic field to the target magnetic fine particle, and a detection that detects a marker composed of the magnetic fine particle species and the target magnetic fine particle Means.

  Furthermore, the method for detecting a marker for a biosensor according to the present invention includes a process of fixing a plurality of magnetic fine particle species together with a biomaterial in the vicinity of a detection region of the biosensor, and a magnetic fine particle species in the vicinity of the plurality of magnetic fine particle types. Providing at least one target magnetic fine particle that is relatively larger than the target, applying an external magnetic field to the target magnetic fine particle, adsorbing the target magnetic fine particles to a plurality of magnetic fine particle species by the external magnetic field, and magnetism And a step of detecting a marker composed of a fine particle type and a target magnetic fine particle adsorbed thereto.

  Here, the adsorption of the target magnetic fine particles with other target magnetic fine particles may be suppressed by the adsorption suppressing means.

  The adsorption suppression means may be a plate-like body that is arranged in parallel with the surface of the detection region at a position spaced apart from the surface of the detection region by a distance wider than the particle size of the target magnetic fine particles.

  The applied external magnetic field may be applied in a direction penetrating the surface of the detection region and applied so that the magnetic field gradient increases toward the side of the surface of the detection region.

  The applied direction of the external magnetic field may be variable.

  The marker may be charged to the same polarity as the surface of the detection region.

  The marker may be detected using any one of a magnetic sensor, a quartz crystal microbalance sensor, a surface plasmon resonance sensor, and an optical microscope.

  Furthermore, the target magnetic fine particles may have a fluorescent material.

  Also, multiple target magnetic particles of different sizes are used, and the target magnetic particles are provided in order from the largest to the smallest, and the types of magnetic particles are determined according to the size of the target magnetic particles to be adsorbed. Measurement may be performed.

  The biosensor marker of the present invention uses a plurality of magnetic fine particle species and a target magnetic fine particle relatively larger than the magnetic fine particle species adsorbed thereto, thereby using a minimal magnetic fine particle species having a size corresponding to DNA. However, there is an advantage that it is possible to measure with high sensitivity using various sensors at low cost. In addition, the use of a plurality of target magnetic fine particles having different sizes also has an advantage that it is possible to quantitatively measure biomaterials.

  The best mode for carrying out the present invention will be described below with reference to the drawings. 2A and 2B are schematic side views for explaining the biosensor marker of the present invention. FIG. 2A is a side view in the vicinity of a sensor portion of the biosensor, and FIG. 2B is an upper surface of the biosensor. FIG. In the figure, the parts denoted by the same reference numerals as those in FIG. Since FIG. 2 is a schematic diagram to the last, the scale and number of each part are not limited to these.

  First, the probe 3 is fixed to the upper part of the sensor part 2 formed in the board | substrate 1 like the conventional method. A predetermined surface treatment is applied to the upper part of the sensor unit 2 so that the probe 3 is fixed. Examples of sensors that can be used as the sensor unit 2 include those using magnetic sensors such as GMR elements, tunnel magnetoresistive effect (TMR) elements, and Hall elements. The probe 3 is selected in advance so as to form a complementary strand with the biomaterial 4 that may be present in the sample to be measured. When the target biomaterial 4 is present in the sample, the biomaterial 4 is complementarily bound to the probe 3. In this way, the biomaterial 4 is fixed in the vicinity of the detection region of the sensor unit. The substrate 1, the biomaterial 4 and the like are immersed in a predetermined aqueous solution.

  On the other hand, the biomaterial 4 is fixed on the surface of the magnetic fine particle seed 10, and the magnetic fine particle seed 10 is configured to be caught by the probe 3 through the biomaterial 4. In the above description, an example in which a biomaterial immobilized on a magnetic fine particle species is caught by a probe has been described. However, the present invention is not limited to this, and the probe is immobilized in advance by complementary binding to the probe. Of course, it is possible to use a magnetic fine particle species that has been surface-treated so as to bind to a biomaterial and to be configured such that the magnetic fine particle species is caught by the biomaterial. As described above, any conventional technique that can be developed in the future can be applied to the method of immobilizing the magnetic fine particle species in the vicinity of the detection region of the sensor unit, and it is possible to indirectly apply biomaterials by measuring the magnetic fine particle species. Any method may be used as long as it can be configured to detect the presence. Further, a technique disclosed in Japanese Patent Application No. 2006-007138 by the same applicant as the present applicant, in which a magnetic particle moving wiring is disposed in the vicinity of the sensor unit in order to appropriately guide the magnetic particle species to the vicinity of the probe or biomaterial. Of course, it is also possible to apply.

  Here, the magnetic fine particle species 10 may be of a size that is not too large relative to the biomaterial. Preferably, for example, a size corresponding to a single molecule DNA, specifically, a particle size of 100 nm or less can be used. By setting the size to this level, the difference in size between the magnetic fine particle species 10 and the biomaterial 4 does not increase, and the coupling between them becomes easy. Further, the magnetic fine particle species 10 may be ferromagnetic or paramagnetic, and various magnetic materials such as ferrite and alnico, more specifically, FePt, Co, Ni, Fe, MnSb, MnAs and the like. Can be applied.

  As an example of more specific immobilization of magnetic fine particle species, as a substrate, for example, CYTOP CTL-809M of Asahi Glass Co., Ltd. having a hydrophobic surface can be used, and a hydrophilic gold film is formed on this substrate. Then, a probe composed of a sulfur atom and a thiol group is fixed to this. On the other hand, as the magnetic fine particle species, for example, commercially available magnetic fine particles having a hydrophilic surface can be used, and an oligo or the like that becomes a biomaterial with biotin attached thereto is fixed.

  A plurality of such magnetic fine particle seeds 10 are provided on the substrate 1, and the plurality of magnetic fine particle seeds 10 are coupled to the probe 3 fixed on the substrate 1, more specifically on the detection region of the sensor unit 2. . In addition, although the detection area of the sensor part 2 may be one, as shown in FIG.2 (b), the detection area (cell) of the sensor part 2 is arrange | positioned on several board | substrates, and several each in this several cell It is also possible to fix the probe. If comprised in this way, it will become possible to use the multiple types of probe which changed the kind for every cell, and it will also become possible to measure simultaneously the various biomaterial which can be respectively couple | bonded with these.

  In the present invention, the target magnetic fine particles 20 that are relatively larger than the magnetic fine particle species 10 are provided with respect to the plurality of magnetic fine particle species 10 thus immobilized on the probe 3 via the biomaterial 4. The target magnetic fine particle 20 may have a particle size larger than that of the magnetic fine particle species 10 and a size that can be detected by the sensor unit 2. For example, it is possible to use target magnetic fine particles having a size of about 5 to 200 times, preferably about 10 to 100 times that of the magnetic fine particle species. More specifically, for example, when the magnetic fine particle seed 10 having a particle diameter of 130 nm is used, the target magnetic fine particle 20 having a particle diameter of 2.8 μm may be used. Further, the size of the cell that is the detection region of the sensor unit 2 may be, for example, about 1 μm to 30 μm, preferably about 3 μm to 15 μm, depending on the size of the target magnetic fine particle 20.

  Further, the target magnetic fine particles 20 may be ferromagnetic or paramagnetic, and various magnetic materials such as ferrite, alnico, and more specifically FePt, Co, Ni, Fe, MnSb, MnAs, and the like. Can be applied.

  Here, the target magnetic fine particles 20 may be charged to the surface of the detection region, that is, to the same polarity as the substrate 1 so that non-specific adsorption does not occur on the substrate 1. This may be performed by plasma processing or the like. By charging the substrate 1 and the target magnetic fine particle 20 to the same polarity, the target magnetic fine particle 20 is electrically repelled from the substrate, so that nonspecific adsorption can be suppressed.

  With such target magnetic fine particles 20 provided on the substrate 1, an external magnetic field is applied from the magnetic field generation source 30 to the target magnetic fine particles 20. An external magnetic field emitted from the magnetic field generation source 30 is applied in a direction penetrating the surface of the detection region of the sensor unit 2 and applied so that a magnetic field gradient increases toward the side of the detection region. Are arranged as follows. As the magnetic field generation source 30, for example, a permanent magnet or a coil can be used. As shown in the side view of FIG. 2A, the external magnetic field as described above can be applied by arranging the magnetic field generation source 30 on the side of the substrate 1. In addition, the polarity of the magnetic field generation source 30 in the illustrated example is an example, and the S pole and the N pole may be reversed.

  When an external magnetic field is applied in this manner, as shown in FIG. 2, the target magnetic fine particles 20 are attracted to and fixed to the plurality of magnetic fine particle seeds 10 by the magnetic field. That is, the magnetic attractive force acts on and attracts the target magnetic fine particle 20 and the plurality of magnetic fine particle seeds 10 so that the N pole and S pole of the magnet attract each other (the state shown in FIG. 2A). As described above, when the target magnetic fine particles 20 are immobilized in the detection region of the sensor unit 2, the presence of the target magnetic fine particles 20 can be detected by the sensor unit 2. Therefore, the presence or absence of the biomaterial can be detected by the presence of the marker composed of the magnetic particle species 10 and the target magnetic particle 20.

  On the other hand, in the region where the magnetic fine particle seed 10 does not exist, the target magnetic fine particles 20 are not adsorbed, and therefore are attracted in the direction in which the magnetic field gradient increases, so the magnetic field generation source 30 side, that is, the left direction in FIG. It flows and is not detected by the sensor unit 2.

  2A shows a state in which an external magnetic field is applied in a direction penetrating the surface of the detection region. However, the present invention is not limited to this, and the external magnetic field is applied to the surface of the detection region. The application direction may be varied as necessary. In order to remove the target magnetic fine particles 20 where the plurality of magnetic fine particle seeds 10 do not exist, the target magnetic fine particles 20 can be efficiently removed by washing while changing the application direction of the external magnetic field.

  As described above, the biosensor of the present invention can increase the marker by immobilizing the large target magnetic fine particles to a plurality of small magnetic fine particle species, so that the sensitivity of the sensor unit 2 is not so high. Even if it exists, it becomes possible to detect the presence of the marker. In other words, the sensor unit 2 can indirectly detect the presence or absence of a biomaterial by measuring the magnetism of a marker composed of a plurality of magnetic fine particle species 10 and target magnetic fine particles 20 fixed thereto. As the marker according to the present invention, a target magnetic fine particle having a particle diameter of, for example, about 1 μm to 20 μm can be used even if the magnetic particle type has a particle diameter of, for example, 100 nm or less. Therefore, the marker can be easily detected even with magnetism that cannot be detected only with the magnetic particle type.

  Here, the marker for the biosensor of the present invention has a relatively large particle size of the target magnetic fine particle 20 with respect to the magnetic fine particle species 10, so that when there is only one magnetic fine particle species 10, for example, Even if the magnetic fine particle 20 is adsorbed to the magnetic fine particle seed 10, the force attracted to the magnetic field generating source 30 becomes larger and is separated from the magnetic fine particle seed 10. Accordingly, the probe 3 to which the plurality of magnetic fine particle species 10 are bonded may be arranged so that the target magnetic fine particle 20 is adsorbed by the plurality of magnetic fine particle species 10. For example, if there are several tens to several hundreds of magnetic fine particle species 10 in the vicinity of the detection region, the target magnetic fine particles 20 can be immobilized.

  From these characteristics, it can be seen that as the particle size of the target magnetic fine particles is increased, a larger amount of the magnetic fine particle species is required to immobilize the target magnetic fine particles on the detection region. FIG. 3 is a graph showing the relationship between the number of magnetic fine particle species (necessary fixing force) capable of fixing the target magnetic fine particle with respect to the particle size. This figure shows the number of magnetic fine particle species actually immobilized on a substrate using a scanning electron microscope, and the relationship between this number and the particle size of the target magnetic fine particles immobilized thereon. is there. From the figure, it can be seen that the number of magnetic fine particle types is proportional to the particle size of the target magnetic fine particles. As described above, since there is some relative relationship between the particle size of the target magnetic fine particle and the number of magnetic fine particles for fixing the target magnetic particle, it is unknown from the particle size of the fixed target magnetic fine particle by using this relationship. It is possible to measure the number of magnetic fine particle species.

  Therefore, if a plurality of target magnetic particles having different sizes are used and are sequentially provided on the detection region in order from the largest to the smallest, the number of the plurality of magnetic particle species immobilized on the detection region can be determined. It becomes possible to measure quantitatively. That is, if the amount of magnetic fine particle species that can be immobilized with respect to the particle size of the target magnetic fine particle is calibrated in advance and a calibration curve is prepared, the number of magnetic fine particle types can be measured. Therefore, if the presence of the target magnetic fine particles cannot be detected by the sensor unit, it can be seen that the number of the magnetic fine particle types relative to the target magnetic fine particle size is small. Then, the particle size of the target magnetic fine particles is gradually reduced, and when the presence of the target magnetic fine particles can be detected by the sensor unit, the number of magnetic fine particle types according to the particle size of the target magnetic fine particles at that time is indirectly measured. It becomes possible.

  If the above-described state is described with reference to FIG. 2B, since many magnetic fine particle species 10 are bound to the probe 3 in the detection region (cell) of the uppermost sensor unit 2 in FIG. Target magnetic fine particles 20 are adsorbed and immobilized on a plurality of magnetic fine particle species 10 in this cell. On the other hand, in the lowermost cell, since the number of the magnetic fine particle species 10 bonded to the probe 3 is small, the target magnetic fine particles 20 are not fixed here but are attracted to the magnetic field generating source 30 side. Further, since the magnetic fine particle seed 10 does not exist in the middle cell, the target magnetic fine particle 20 is not fixed to this cell. Note that a plurality of cells may be arranged in a row as in the illustrated example, or may be arranged in a matrix. Of course, the biomaterial may be measured using only one cell.

  As described above, in the biosensor of the present invention, the number of the magnetic fine particle species can be quantitatively measured by detecting the target magnetic fine particles, and thus the quantitative amount of the biomaterial can be measured. In order to further improve the accuracy of quantitative measurement, it is possible to provide a plurality of detection regions (cells) of the sensor unit, which is a region to which the magnetic fine particle species are immobilized, and perform measurement by averaging.

  Here, a plurality of target magnetic fine particles 20 may be adsorbed in a columnar shape along the direction of the magnetic field due to the influence of a magnetic field applied in a direction penetrating the surface of the detection region by the magnetic field generation source 30. This phenomenon is also described in the above-mentioned Japanese Patent Application No. 2006-310712 by the same applicant as the present applicant. When the target magnetic fine particles are adsorbed in a plurality of columns, it adversely affects the quantitative measurement of the magnetic fine particle species, and this is preferably prevented. Therefore, the biosensor of the present invention may be configured to suppress adsorption with other target magnetic fine particles.

  A method for suppressing adsorption will be described with reference to FIG. FIG. 4 is a schematic side view for explaining a method for suppressing adsorption between target magnetic fine particles in the biosensor of the present invention. In the figure, portions denoted by the same reference numerals as those in FIG. As shown in the drawing, a plate-like body 40 is arranged in parallel to the surface of the detection region at a position spaced apart from the surface of the detection region of the sensor unit 2 of the substrate 1 by a predetermined distance. More specifically, the plate-like body 40 is disposed at a distance wider than the particle size of the target magnetic fine particle 20. More specifically, the distance from the surface of the detection region where the plate-like body 40 is disposed is preferably larger than the particle size of the target magnetic fine particle 20 and narrower than twice the particle size of the target magnetic fine particle 20. . Since the target magnetic fine particles 20 tend to be attracted in a columnar shape along the direction of the magnetic field, it is possible to suppress the target magnetic fine particles 20 from being attracted in a columnar shape by arranging the plate-like body 40 at the above-described position. It becomes. Here, as the plate-like body 40, for example, a glass plate can be used.

  The plate-like body 40 may be fixed in advance so as to maintain a predetermined position with respect to the substrate 1, or may be provided so as to cover from above the substrate after providing the target magnetic fine particles and the like. Even if the plate-like body 40 is fixed to the substrate 1 in advance, it can be fixed to the sensor unit 2 by providing the target magnetic fine particles from the side.

  As another method for suppressing adsorption, for example, by making the substrate surface hydrophilic by plasma treatment or the like, the amount of the aqueous solution covering the substrate is reduced, and the degree of freedom in the height direction of the target magnetic fine particles is reduced. Therefore, it is also possible to suppress columnar adsorption of the target magnetic fine particles.

  In this way, by suppressing columnar adsorption along the direction of the external magnetic field of the target magnetic fine particles, it is possible to more accurately measure the type of magnetic fine particles.

  In the above-described examples, the sensor of the sensor unit 2 has been exemplified by using a magnetic sensor such as a GMR element, a TMR element, or a Hall element. However, the present invention is limited to this. It is not a thing. The marker according to the present invention not only enhances magnetism by the target magnetic fine particles 20 but also increases the mass and size as compared with a single magnetic fine particle species. Therefore, in addition to the magnetic sensor, it is possible to easily detect the presence or absence of a marker using, for example, a quartz crystal microbalance sensor or a surface plasmon resonance sensor.

  Here, the quartz crystal microbalance sensor is a mass sensor that uses the characteristic that the frequency decreases when a substance adheres to the surface of the quartz crystal. The surface plasmon resonance sensor is a sensor that utilizes the phenomenon of surface plasmon resonance in which the intensity of reflected light attenuates as the angle of incidence of the laser on the gold thin film changes. In a crystal microbalance sensor or surface plasmon resonance sensor, even if the magnetic fine particle species alone is too small to measure changes in frequency or refractive index, the marker of the present invention can be used for target magnetic fine particles. Since the mass is enhanced, the measurement can be easily performed.

  Further, since the marker according to the present invention has an increased size, the marker can be directly detected by an optical microscope or the like. Since the optical microscope has a theoretical resolution of about 100 nm and actually about 250 nm, fine particles smaller than that could not be observed. However, if the marker of the present invention is used, the size becomes about several μm depending on the target magnetic fine particles, so that it is possible to easily observe the marker with an optical microscope without using an expensive and large electron microscope. It is also possible to add a fluorescent substance to the target magnetic fine particles and detect the marker by the light.

  Note that the biosensor marker of the present invention is not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention. In addition, it should be understood that the dimensions and numbers given in the above description and illustrated examples are not limited to these.

  Furthermore, the detection sensor to be applied is not limited only to the above-described illustrated examples and explanations, and a combination of these may be used to detect the marker by a plurality of means. Further, the application of the external magnetic field is not limited to the one that is applied after the target magnetic fine particles are supplied, but may be the one that is always applied.

FIG. 1 is a schematic side view for explaining a marker measurement method of a conventional biosensor. 2A and 2B are schematic side views for explaining the biosensor marker of the present invention. FIG. 2A is a side view in the vicinity of a sensor portion of the biosensor, and FIG. 2B is an upper surface of the biosensor. FIG. FIG. 3 is a graph showing the relationship of the number of types of magnetic fine particles that can be fixed to the particle size of the target magnetic fine particles. FIG. 4 is a schematic side view for explaining a method for suppressing adsorption between target magnetic fine particles in the biosensor of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Sensor part 3 Probe 4 Biomaterial 5 Magnetic fine particle 10 Magnetic fine particle seed | species 20 Target magnetic fine particle 30 Magnetic field generation source 40 Plate-shaped body

Claims (22)

A marker for a biosensor, the marker being
A plurality of magnetic fine particle species fixed together with the biomaterial in the vicinity of the detection region of the biosensor;
At least one target magnetic fine particle that is adsorbed to the plurality of magnetic fine particle species by application of an external magnetic field and is relatively larger than the magnetic fine particle species;
A biosensor marker comprising:   2. The biosensor marker according to claim 1, wherein the target magnetic fine particles are suppressed from being adsorbed by other target magnetic fine particles by an adsorption suppression unit. 3.   3. The biosensor marker according to claim 2, wherein the adsorption suppression means is a plate-like shape arranged in parallel with the surface of the detection region at a position spaced apart from the surface of the detection region by a distance wider than the particle size of the target magnetic fine particles. A biosensor marker characterized by being a body.   The biosensor marker according to any one of claims 1 to 3, wherein the external magnetic field to be applied is applied in a direction penetrating the surface of the detection region and directed to a side of the surface of the detection region. The biosensor marker is applied so that the magnetic field gradient increases.   The biosensor marker according to any one of claims 1 to 4, wherein the applied direction of the applied external magnetic field is variable.   The biosensor marker according to any one of claims 1 to 5, wherein the marker is charged to the same polarity as the surface of the detection region.   The biosensor marker according to any one of claims 1 to 6, wherein the marker is detected using any one of a magnetic sensor, a quartz crystal microbalance sensor, a surface plasmon resonance sensor, and an optical microscope. A marker for biosensors.   The biosensor marker according to any one of claims 1 to 7, wherein the target magnetic fine particles have a fluorescent substance. A biosensor for detecting a biomaterial using a marker, the biosensor
A plurality of magnetic fine particle species fixed together with the biomaterial in the vicinity of the detection region of the biosensor;
At least one target magnetic fine particle that is adsorbed to the plurality of magnetic fine particle species by application of an external magnetic field and is relatively larger than the magnetic fine particle species;
An external magnetic field applying means for applying an external magnetic field to the target magnetic fine particles;
Detection means for detecting a marker comprising the magnetic fine particle species and the target magnetic fine particles;
A biosensor comprising:   The biosensor according to claim 9, further comprising an adsorption suppression unit that suppresses adsorption with other target magnetic fine particles.   The biosensor according to claim 10, wherein the adsorption suppression unit is a plate-like body that is arranged in parallel to the surface of the detection region at a position spaced apart from the surface of the detection region by a larger distance than the particle size of the target magnetic fine particles. A biosensor characterized by being.   The biosensor according to any one of claims 9 to 11, wherein the external magnetic field applying unit applies an external magnetic field in a direction penetrating the surface of the detection region and toward a side of the surface of the detection region. A biosensor characterized by applying an external magnetic field so as to increase a magnetic field gradient.   The biosensor according to any one of claims 9 to 12, wherein the external magnetic field applying unit is capable of changing an application direction of an external magnetic field to be applied.   The biosensor according to any one of claims 9 to 13, wherein the surface of the detection area of the biosensor is charged to the same polarity as the marker detected by the detection means.   15. The biosensor according to claim 9, wherein the detection means is any one of a magnetic sensor, a quartz crystal microbalance sensor, a surface plasmon resonance sensor, and an optical microscope. Sensor.   The biosensor according to any one of claims 9 to 15, wherein the target magnetic fine particles of the marker detected by the detection means include a fluorescent substance. A method for detecting a marker for a biosensor, the method comprising:
A process of fixing a plurality of magnetic fine particle species together with a biomaterial in the vicinity of a detection region of the biosensor;
Providing at least one target magnetic particulate relatively larger than the magnetic particulate species in the vicinity of the plurality of magnetic particulate species;
Applying an external magnetic field to the target magnetic fine particles;
A process of adsorbing the target magnetic fine particles to the plurality of magnetic fine particle species by the external magnetic field;
Detecting a marker composed of the magnetic fine particle species and the target magnetic fine particles adsorbed thereto;
A marker detection method for a biosensor, comprising:   18. The biosensor marker detection method according to claim 17, wherein the step of applying the external magnetic field uses adsorption suppression means for suppressing adsorption with other target magnetic fine particles. Method.   19. The biosensor marker detection method according to claim 18, wherein the adsorption suppression unit is arranged in parallel to the surface of the detection region at a position spaced apart from the surface of the detection region by a distance wider than the particle size of the target magnetic fine particles. A marker detection method for a biosensor, which is a plate-like body.   20. The biosensor marker detection method according to claim 17, wherein the step of applying the external magnetic field includes applying an external magnetic field in a direction penetrating the surface of the detection region and detecting the surface of the detection region. A marker detection method for a biosensor, wherein an external magnetic field is applied so that a magnetic field gradient increases toward the side of the biosensor.   21. The biosensor marker detection method according to claim 17, wherein in the step of applying the external magnetic field, an application direction of the external magnetic field is variable. Method. The biosensor marker detection method according to any one of claims 17 to 21, wherein the step of providing the target magnetic fine particles uses a plurality of target magnetic fine particles of different sizes, in order from the largest to the smallest. , Providing target magnetic fine particles sequentially,
The marker detection method for a biosensor, wherein the step of detecting the marker performs quantitative measurement of the plurality of magnetic fine particle species according to the size of the target magnetic fine particles to be adsorbed.